1. Field of the invention
The present invention relates to compounds that are therapeutic, and more particularly, to compounds that are effective in treating pain, cancer, multiple sclerosis, Parkinson's disease, Huntington's chorea and/or Alzheimer's disease.
2. Discussion of Relevant Technology
Pain management has been studied for many years. Cannabinoid receptor (e.g., CB1 receptor, CB2 receptor) ligands such as agonists, antagonists and inverse agonists may produce relief of pain in a variety of animal models by interacting with CB1 and/or CB2 receptors. Generally, CB1 receptors are located predominately in the central nervous system, whereas CB2 receptors are located primarily in the periphery and are primarily restricted to the cells and tissues derived from the immune system.
While CB1 receptor agonists and mixed (CB1/CB2) receptor agonists, such as tetrahydrocannabinol (THC) and opiate drugs, are effective in anti-nociception models in animals, they tend to exert many undesired CNS side-effects, e.g., psychoactive side effects and the abuse potential of opiate drugs. These undesired CNS side effects are known to be mediated by the CB1 receptors. In contrast, CB2 receptor agonists may manage pain in humans or animals without causing those undesired CNS side effects due to the general location of CB2 receptors and other factors.
Therefore, there is a need for CB2 receptor ligands such as agonists useful in managing pain and/or treating other symptoms or diseases.